Avian Influenza

Avian Influenza (AI) is an infectious viral disease of birds (especially wild waterfowl such as ducks and geese), often causing no apparent signs of illness. AI viruses can sometimes spread to domestic poultry and cause large-scale outbreaks of serious disease. Some of these AI viruses have also been reported to cause disease or subclinical infections in humans and other mammals.

AI viruses are divided into two groups based on their ability to cause disease in poultry: high pathogenicity (HPAI) or low pathogenicity (LPAI). HPAI results in high death rates (up to 100% mortality within 48 hours) in some poultry species. LOAP also causes outbreaks in poultry but is not generally associated with severe disease.

To report sick birds or unusual bird deaths:​

  • Sick birds or birds that have died from unknown causes:

    • Call the Avian Health Hotline at Colorado State University (CSU): (970)297-4008

  • Dead birds:

    • Submit to the CSU Veterinary Diagnostic Laboratory in Fort Collins for free HPAI Testing: (970)297-4008 or (970)297-1281

  • Multiple sick birds or multiple unusual bird deaths:

    • Call the Colorado State Veterinarian’s Office (303)869-9130 or the USDA-Veterinary Services Colorado Office (303)231-5385


Colorado Department of Agriculture: Poultry Emergency Disease Response Plan

Colorado Department of Agriculture: Secure Egg Supply Plan

USDA Avian Influenza Website

USDA Biosecurity for Birds for Backyard Flocks

USDA Biosecurity Information for Commercial Poultry

US POULTRY Self-Assessment of Enhanced Biosecurity

HPAI: A Guide to Understanding the Response Process

American Veterinary Medical Association: Avian Influenza FAQ

Center For Disease Control and Prevention (CDC): HPAI Information

OIE Avian Influenza Portal

Poultry Show and Exhibition Guidelines


Avian Influenza Technical Services 2018 Spanish

Avian Influenza Commercial Farmers 2018Spanish

Avian Influenza Backyard Producers 2018Spanish

Press Releases

April 2020: USDA Confirms Highly Pathogenic H7N3 Avian Influenza in a Commercial Flock in South Carolina